Most of the solutions for optical interconnects presented on the market use 1-dimensional arrays of optical sources and receivers. These solutions, which give excellent performance for small arrays, are not scalable and cannot work with a large number of optical sources and receivers. In order to send and transfer a large amount of data, the array approach does not work, and 2-dimensional matrices must be used.
With small arrays, the connection from the electronic elements (drivers on the side of the transmitter and amplifiers on the side of the receiver) to the optical elements (such as VCSELs and photodiodes, accordingly) is carried out by bonding, while the electronic driving chip is relatively simple. When the larger and 2-D matrix is used, the electronic circuits are more complicated and more electrical power is required. Heat dissipation problems are observed and frequently thermo-stabilization is required. Also, connection of a large bundle of lenses and fibers to the matrices of VCSELs and photodiode chips is required, and mechanical, as well as thermal, stability of the resulting assembly is crucial.
In conventional interconnects, either there is no optical interface, or the active optical elements do not generate very much heat, so no heat sink is required, or the active optical elements are mounted on the PCB and cooled by a heat sink.